This invention relates to an electronic clinical thermometer, of approximately the same size as the conventional glass clinical thermometer, for taking a patients temperature electronically and for displaying the temperature digitally or in the form of a bar signal.
An electronic clinical thermometer generally comprises an elongate hollow enclosure for accommodating a temperature sensing element which converts temperature information into an electrical signal, a measuring unit for converting the electrical signal into a processable signal, an arithmetic unit for computing the temperature from the converted signal, a display unit for displaying the temperature computed by the arithmetic unit, a battery for supplying the abovementioned units with electrical power, and a switch connected between the battery and each unit.
Conventional electronic clinical thermometers employ manually operable means such as a slide switch for the abovementioned switch. A switch of such type has a knob which protrudes from the enclosure. When the thermometer is immersed in a disinfectant such as alcohol for the purpose of maintaining hygiene, the result can be poor switch contact as well as system malfunction due to corrosion of the electronic circuitry through the protruding portion of the switch into the electronic clinical thermometer. Though these defects can be improved upon by adpoting a water-proof construction at the location where the switch knob protrudes from the enclosure, such an expedient is disadvantageous in that the switch has a complicated structure and is large in size and that higher costs are entailed. Furthermore, since the switch has a mechanical structure and must possess sufficient durability and reliability, a major reduction in size is not possible. Accommodating a mechanical switch leads to an enclosure of enlarged diameter and makes it difficult to reduce the size of the thermometer to that of a mercury thermometer, even though electronic circuit attains reduction in size. Also, since electronic clinical thermometers rely on digital circuitry, a loss of battery power is large when the user forgets to turn off the switch and, since the battery is of small capacity, the battery will run down and become useless in a shorter period of time in comparison with electronic thermometers that use analog circuitry.